Electric motion equipment often comprises a number of flexible electric power cables for transferring electric power.
An example of an area of use comprises a moving environment is a modern wind turbine wherein the rotating part such as the wind turbine rotor and hub includes a lot of electric motion equipment with accompanying power cables.
The power cables often follow the motions of the electric motion equipment in the wind turbine e.g. continuous forward and backward linear movements. Simultaneously the electric motion equipment and power cables perform a rotating movement with the rotating part. Consequently the cables face linear and rotating forces from the different movements.
A modern power cable usually comprises a conductor surrounded by an isolating cover of a PVC material. The cable is terminated in a cable shoe or a similar connection device in order to be able to connect the cable to the electric motion equipment. The cable shoe is applied with a mechanical force to an end of the cable where the cable end has initially been stripped of isolating cover.
A problem of modern power cables with connection to electric motion equipment is the fact that metal fatigue failure may occur due to the linear and rotational movements. The fatigue failures especially occur at the place of mechanical deformation in the connection between the cable and the cable shoe. Consequently the cables need to be replaced more often than cables just facing forward and backward linear movements.
It is an object of the present invention to provide a flexible electric power cable without the abovementioned problem. Further, it is an object of the present invention to provide a wind turbine with a flexible electric power cable advantageously adapted to the place of use.